      ((vowel-formant (overtone.sc.ugen-collide/+ freq (sin-osc:kr (* 1.5 kr-mul))) freq-c q)))))
 
 (definst drone-eh
+  "a testing instrument, not used in runtime"
   [freq 100]
   (let [eq-freq      [530 1840 2480]
         q            0.1

   ::release 5.0
   ::gate 1})

(defn tremelo-freq []
  (fn [] (sin-osc:kr 0.5)))

(s/fdef vowel-formant
        :args (s/cat :freq number? :eq-freq number? :q number?)
        :ret (s/fspec :args (s/cat :saw clojure.test/function? :freq number?)
                      :ret number?))

(defn vowel-formant [freq eq-freq q]
  (fn [] (resonz (saw freq) eq-freq q)))

(defn synth-unit-layered [freq eq-freq q kr-mul]
  (let [[freq-a freq-b freq-c] eq-freq]

    (>= age 1000) 0.4
    :else 1))

(defn end-sound! [pid]
  (if (contains? @person-sound pid)
    (do
